This invention relates to swim fans that are commonly used when skin-diving or scuba diving. The reason for using a swim fin is to obtain a greater propulsive effect than is obtainable with the human foot alone. The swim fins generally consist of a foot portion to receive the swimmer's foot, plus a blade portion which forms a forward extension of the foot portion. The blade portion increases by several times the area of surface that reacts against the water and thus propels the swimmer by reaction.
In the past, most swim fans have been made of rubber with the blade portion being flexible so that it would bend in the direction opposite to which the fin is traveling. Later models of swim fans have been designed with water-flow channels on the blade portion to increase the thrust developed from the fin during the driving stroke of the swimmer's leg kick. As always, man continues to desire even greater performance from improved swim fins.
It is an object of the present invention to provide a swim fin having an improved blade portion structure.
It is also an object of the invention to provide a swim fin whose structure allows the flexible blade portion to develop a reverse curve configuration during the kicking stroke.
It is a further object of the invention to provide a swim fin whose configuration during the kicking stroke produces an accelerating surface along the blade portion for the water being displaced rearwardly.